At least 10 people have been killed and two dozen others wounded in three weekend mass shootings in the US, the latest in a string of deadly gun attacks that have left politicians scrambling to tackle the crisis. The shootings — late on Saturday in Philadelphia and early on Sunday in Chattanooga, Tennessee — have further jolted a country facing <a href="https://www.thenationalnews.com/world/us-news/2022/05/25/deadliest-mass-shootings-in-recent-us-history/" target="_blank">a gun violence epidemic </a>that has already claimed several thousand American lives this year and shows no signs of abating. In Saginaw, Michigan, three people were killed and two others wounded in a shooting on Sunday, MLive.com and WEYI television reported. And in Clarendon County, South Carolina, five teenagers and a 12-year-old were among seven wounded in a shooting at a graduation party on Saturday that killed one adult, police said in a statement. They come as polarised US senators find themselves under pressure to craft a measure that codifies at least basic, preliminary steps to help reduce the carnage. In Philadelphia, two men and a woman were killed when multiple shooters reportedly opened fire on a crowd in a popular South Street nightlife area. Philadelphia Police Commissioner Danielle Outlaw said one of the victims had got into a fight with another man, which could have been the cause of the shooting. The two others were “innocent bystanders,” she told reporters. Another bystander, Joe Smith, 23, told <i>The Philadelphia Inquirer</i> that his mind had flashed to the recent incidents when he heard the first shots ring out on Saturday. “Once it started I didn't think it was going to stop,” he said. “There was guttural screaming,” he added. “I just heard screams.” An eruption of violence in Chattanooga resulted in 14 people being shot, including two fatally, while another person was killed and two more were injured after they were struck by vehicles fleeing the scene, police chief Celeste Murphy said, adding “several” victims remained in critical condition. The pre-dawn incident occurred near a nightclub in a downtown area of the city of 180,000. As of mid-Sunday no arrests had been made in either case, according to Ms Murphy and Philadelphia media. Such gun violence has become almost commonplace in America, but the shock felt over recent mass shootings at a grocery store in Buffalo, New York and a <a href="https://www.thenationalnews.com/world/us-news/2022/05/27/it-was-the-wrong-decision-not-to-breach-uvalde-classroom-texas-official-says/" target="_blank">primary school in Uvalde, Texas</a> have spurred cries for action. Democratic Senator Chris Murphy has been working with a bipartisan group of senators on reform measures — a difficult task with Republicans routinely rejecting most forms of gun control. Mr Murphy said on Sunday the group hoped to hammer together a legislative package that draws at least 10 Republican votes on top of expected support from nearly every Democrat. “I think the possibility of success is better than ever before,” he told CNN. The emerging package, he said, would probably include “significant mental health investment, school safety money, and some modest but impactful changes in gun laws,” including an expansion of background checks for gun buyers. There have been at least 239 US mass shootings this year, according to the Gun Violence Archive, a non-profit research group. It defines a mass shooting as one in which at least four people are shot, excluding the gunman. “Congress needs to do their jobs and pass common-sense regulation that will help stop this nonsense,” angry Chattanooga mayor Tim Kelly told reporters. He called for “mandatory background checks and prohibiting high-capacity magazines that allow shooters to hurt dozens of people without even having to reload.” Republican Congressman Jim Jordan accused Democrats of wanting “to take your guns.” During warmer months, gun violence tends to spike in the US, where there were an estimated 393 million guns in circulation in 2020, exceeding the number of citizens. The Texas shooting prompted <a href="https://www.thenationalnews.com/world/us-news/2022/05/30/biden-sees-chance-of-rational-republican-gun-approach/">Congress</a> to attempt to tighten the nation's notoriously lax gun laws, though meaningful reform have been thwarted time and again in the past. In 2020, at least 45,222 people died from gun-related injuries in the US, according to <a href="https://www.pewresearch.org/fact-tank/2022/02/03/what-the-data-says-about-gun-deaths-in-the-u-s/" target="_blank">a Pew Research Centre analysis of data</a>, based mainly on the Centres for Disease Control and Prevention (CDC) and the FBI. The year 2020 is the most recent year for which complete data are available. Deaths included gun murders and gun suicides. <i>News agencies contributed to this report</i>